No Man's Sky can drop as far as 13FPS in some stages and suffers from distracting texture pop-ins on ship fly-bys.
I'm enjoying my time with No Man's Sky so far--the game is absolutely beautiful and is quite an interesting experience. However I am aware of its faults, some of which are glaring distractions that really break the immersion. Some of the major faults are the ugly texture pop-ins that occur when you're flying above land in your ship, and Digital Foundry has found that No Man's Sky can dip far below its 30FPS mark--as low as 13FPS in some cases.
Now before we start dismissing Hello Games' procedurally generated exploration sim as a "broken game," we need some context. The game handles its frame rates exceedingly well on Sony's PlayStation 4, providing near-consistent 30FPS in almost every moment--even during cluttered space battles with frigate ships, planets, asteroids and pirates blasting you down, as well as high-volume planets with tons of flora and fauna. But there's some moments that trigger some noticable FPS drops, namely when you're flying across a new planet's surface.